"count" is unsigned so checking for less than zero here causes a static
checker warning.  And really it's better to let the access_ok() check
fail if the user passes in a NULL "buf" pointer because -EFAULT is the
correct error code.
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>